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Same Great Applications and Articles,
Now in a More Earth-Friendly Format
The award winning BioProbes® Journal for Cell Biology Applications is now available as a web publication, too.

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what they are
The popular pHrodo™ dye, a fluorogenic pH sensor for endocytosis in live-cell studies, is now offered in two additional formats: as a microscale antibody/protein labeling kit, and as an avidin conjugate for use with any biotinylated target. pHrodo™ dye exhibits pH-sensitive red fluorescence that increases in intensity with increasing acidity. pHrodo™ dye is essentially dark in the extracellular environment but exhibits bright red fluorescence at pH 5–7 as it undergoes endocytosis. Although we call the dye pHrodo™ Red, these products contain the same pHrodo™ dye as our pHrodo™, SE; pHrodo™ dextran; and pHrodo™ BioParticles® for phagocytosis.

what they offer

Flexibility to create your own probes for phagocytosis and endocytosis investigations

Compatibility to multiplex with green dyes such as GFP, fluo-4, and calcein

Designed and tested for imaging, flow cytometry, and HTS/HCS (microplate) applications

how they work
pHrodo™ Red Avidin and the pHrodo™ Red Microscale Labeling Kit offer a rapid means to make any material, including proteins, peptides, viruses and small molecules a pHrodo™ Red conjugate. The labeling kit includes reagents for 3 labeling reactions of 20–100 µg protein with excellent recovery, and can also be used for labeling viruses. Alternatively pHrodo™ Red Avidin can be used to create bioconjugates using the easy, high-affinity avidin–biotin interaction. Use pHrodo™ Red Avidin when a biotinylated target already exists.

New Recombinant Antibodies—LRRK2 ABfinity™ Antibodies

what they are
Leucine-rich repeat kinase 2 (LRRK2) is phosphorylated at serine 935 in brain tissue and is implicated in familial Parkinson’s disease. When LRRK2 is phosphorylated at serine 935, the 14-3-3 protein binds specifically, and this may be an important mechanism in regulating dopamine physiology.

what they offer
ABfinity™ recombinant monoclonal and oligoclonal antibodies offer consistent results, minimizing the need to revalidate working antibody dilutions for your experiments each time you order.

Indirect ELISA was performed using the indicated concentrations of LRRK2 phosphoserine 935 [pS935] Rabbit Recombinant Oligoclonal Antibody (Cat. No. 710097) to detect phospho-LRRK2 peptide coated onto the plate. A nonlinear regression analysis was performed (4 PL), and LOD and LOQ for the antibody were determined to be 450 pg/mL and 1,370 pg/mL, respectively.

what they are
The ribosomal p70S6 kinase is known for its role in modulating cell-cycle progression, cell size, and cell survival. Activated p70S6 kinase is phosphorylated at threonine 421 and serine 424, and higher phosphorylation levels are associated with neurofibrillary pathology in Alzheimer's disease.

what they offer
ABfinity™ recombinant monoclonal and oligoclonal antibodies offer consistent results, minimizing the need to revalidate working antibody dilutions for your experiments each time you order.

In a recent study, Gasparian et al. published results that help elucidate the mode of action of a class of small molecules, curaxins, that have the potential to be useful in cancer therapy (Sci Transl Med 3, 95ra74 (2011)). They found that this newly identified class of anti-cancer compounds exhibits activity in mice at levels that are not toxic or genotoxic—an unusual property for DNA-targeted chemotherapeutics. In addition, they show that these compounds “simultaneously activate p53 and inhibit NF-κB”, proteins that are dysregulated in many malignant tumor types. CellLight® Histone 2B-RFP, BacMam 2.0 was used in this study to help show that curaxins cause functional inactivation of the FACT (facilitates chromatin transcription) complex by causing one of its two subunits, structure-specific recognition protein 1 (SSRP1), to become tightly associated with chromatin.

PROVEN PERFORMERS

Accurate—without the subjectivity of manual cell counting and user-to-user variability

Fast—total cell counts, percent viable cells, and average cell size in as little as 30 seconds

Versatile—can be used with a wide variety of cells: documented with 120 different cell types from 18 species so far

Convenient—requires no cleaning or routine maintenance, and minimal setup

Have confidence in your cell counts with the Countess® Automated Cell Counter, which has been referenced in over 100 peer-reviewed publications representing over 120 different cell types from 18 species. The Countess® Automated Cell Counter is a benchtop instrument that offers easy and accurate cell and viability counts in as little as 30 seconds. This image-based cell counting instrument eliminates the tedium and subjectivity of manual cell counting and minimizes subjective judgments that can lead to errors. By offering accurate cell count, cell size, and cell viability data, the Countess® instrument aids in improving downstream results, which translates to fewer experimental repeats needed due to subjective errors. To supplement the peer-reviewed publications, we have generated several technical and application notes covering topics such as counting blood, primary cells, and stem cells.

The Countess® Automated Cell Counter continues to set the standard for benchtop cell counters.

From the Bench

There have have been several outbreaks of deadly Escherichia coli in the last few years; the US Centers for Disease Control and Prevention (CDC) lists six such events in 2010 and 2011, with the sources of contamination covering a wide range of food products that include beef, lettuce, cheese, and nuts. Shiga toxins produced by certain strains of E. coli and Shigella dysenteriae are responsible for the severe illness and death that can result when humans become infected with these bacteria. It is hoped that research aimed at better understanding the effect of shiga toxins on host cells will help identify strategies for effective treatment and/or prevention of illness. To that end, scientists at the Texas A&M Health Science Center and colleagues recently compared intracellular trafficking and autophagosome formation of shiga toxin in toxin-sensitive and toxin-resistant cells. They were particularly interested in understanding whether autophagy in response to shiga toxin is a protective mechanism or whether it contributes to apoptosis. They found that shiga toxin was translocated to different cell compartments in toxin-sensitive and -resistant cells. In addition, they report that both cell types exhibited autophagosome formation. They determined that “proteolytic cleavage of Atg5 and Beclin-1 plays pivotal roles in switching non-cytotoxic autophagy to cell death signalling.”